Galloping not such hard work

Recent research has found that horses do less work moving through their environment than has been reported previously.

Earlier studies have estimated the external work of the moving horse from measurements taken using techniques such as 3D motion analysis. Now, researchers from the Royal Veterinary College (RVC) have used force plate technology to measure the external work of galloping in racehorses. The study has been published in the journal Biology Letters.

This new research, conducted by academics working in the RVC’s Structure and Motion Lab, measured the forces exerted by the horse on the ground. Sensors were buried under a section of the racing surface at the British Racing School in Newmarket. A professional jockey then rode seven thoroughbred racehorses over this specialist equipment, allowing the researchers to measure directly the external mechanical work of galloping by measuring the forces they exerted on the runway.

Sensors were buried under the track surface

The RVC’s study produced lower values than those previously reported for external work (the work a horse needs to do to move relative to its environment) in galloping horses. Estimated via different methods, those previously reported high external work values are at odds with the fact that horses evolved to move at high speeds over long distances. A high external work value would make moving over long distances much harder. The RVC’s new results support that thinking.

The research team were then able to calculate the apparent muscle efficiency of galloping horses by combining the external work values from this study with published values for metabolic work (the conversion of food into energy used by muscles) and internal mechanical work (how much work is needed to move the limbs relative to the body). They found that the horse’s efficiency values were between 37-46%.

The researchers expect that the findings will provide useful insight into the movement of racehorses and will contribute details towards explaining how racehorses can gallop so efficiently over long distances.

Commenting on the unique methodology of the study, Dr Zoe Self Davies, Postdoctoral Research Associate at the RVC, said: “This was really challenging data to collect and, to our knowledge, it is the first time high speed galloping force plate data have been collected from such a large animal.”

For more details, see:

External mechanical work in the galloping racehorse

Z. T. Self Davies, A. J. Spence and A. M. Wilson.

Biology Letters (2019) vol 15

doi.org/10.1098/rsbl.2018.0709